I was having trouble making a vanilla zero-crossing pitch detector for my project, so I ported one I had done in c++ to a pd external. maybe useful to others? https://github.com/brianlindgren/zDet/

i realized that i obviously didn't follow all categories on this forum - so i missed your post and this response comes a little late. anyway: thanks for sharing! it reminded me of my approach for a vanilla pitch tracker. i now also realized that i didn't need a [block 1] for a 1-sample delay (which was there until today), but could use [rzero~] instead:

patch: zc_pitchtrack~.pd

nice implementation and very resourceful approach using the vanilla objects. thx for sharing! will save this for future reference